紙片-電噴灑質譜技術對4-氯安非他命快速篩選法的開發與研究

Abstract

本研究以4-氯安非他命為測試樣品，探討紙噴灑-質譜法中，紙片材質對電噴灑效果及偵測靈敏度的影響。實驗中使用兩個系列的紙片來作討論，一個系列是以天然纖維製成的紙張，包括雁皮紙、典具帖紙、格拉辛紙及蟬翼紙。實驗結果發現，以雁皮紙效果最好，這是因為雁皮紙不僅韌且薄，厚度<20 µm。作為電噴灑片時，僅需~30秒即可將樣品全部電噴灑釋放。這可使質譜儀瞬間接收到大量的離子，有助於提高偵測的靈敏度，比起傳統使用的層析濾紙低~1個數量級。在相同條件下選用的濾紙其厚度則>100 µm，樣品會擴散至整張濾紙。樣品溶液需要1.5分鐘以上才能將部分紙片中的樣品噴灑完畢，部分樣品會殘留在紙片上，導致偵測極限較差。有鑑於天然纖維在實驗室中製作困難，因此本研究以電紡法噴製聚乳酸、聚碳酸及醋酸酯等3種微孔薄膜陣列來進行比較。實驗發現，薄、纖維規律排列且具疏水性的聚碳酸薄膜紙 (~70 μm)，比濾紙的偵測極限好了近1個數量級。這是因為疏水且較薄的紙，可以快速的將樣品電噴灑進入偵測器，且偵測時間少於1分鐘。後面將就各紙張利用掃描式電子顯微鏡拍攝的圖片來作討論。製作薄膜纖維的方法及唾液樣品的偵測在後續都會討論。Compared to the chromatography paper currently used in paper-spray mass spectrometry (PS-MS), two series of “papers” were examined, including the papers that were made from natural and synthetic fibers, respectively. In the former case, 4 types of Japanese paper (Washi) were used, including Gampi paper, Tengujou paper, Glassine paper and Cicada paper, and the findings show that the limit of detection can be dramatic improved only when Gampi paper was used. This is because Gampi paper is very toughness and extremely thin (thickness,<20 μm) rather than the chromatography paper (thickness, >100 μm) and the others, leading to the sample solution much easier to be ejected and ionized toward the mass inlet. Since ionization occurs within a very short period (less than 30 seconds), an abundance of ions is formed, leading to a dramatic improvement in the limit of detection, at least 10-fold than the use of the chromatography paper. Due to natural fibers are difficult prepared in laboratory, in the case of synthetic fibers, 3 types of microtube array membranes were synthesized from polycarbonate (PC), polylactic acid (PLA) and cellulose acetate (CA) respectively, by means of co-axial electrospinning technique. The findings show that the limit of detection also can be improved, almost 10-fold, when the PC membranes were used. This is because PC membranes were thin (thickness,<70 μm), hydrophobic and sequence with the directionality, resulting to ionization occurs within a very short period (less than 1 min). Hence, as a rapid screening tool based on the PS-MS, both of the uses of Gampi paper and PC membrane were very useful. Furthermore, clear SEM (scanning electron microscope) photos of Gampi paper, PC membrane and chromatography paper were shown and discussed. Detailed information on how to synthesize PC membranes, the optimized position for ionization and its application for the analysis of a saliva sample are also reported.